Timing of puberty and infertility in women and men

To study the association between puberty and infertility.

The study population consisted of 3,303 women and 2,522 men born into the Danish Healthy Habits for Two cohort (1984-1987). In 2005, the participants reported age at menarche and voice break. In the main analysis, pubertal timing was categorized into three groups of approximately equal size. Women were categorized as having earlier (<13 years), average (13 years) or later (>13 years) age at menarche (mean: 13.3 years), and men as having earlier (<14 years), average (14 years) or later (>14 years) age at voice break (mean: 14.5 years). Infertility diagnoses and use of assisted reproductive technologies in participants and their partners were obtained from Danish registries. Three infertility definitions were used: Model 1 (all registry-identified infertility), Model 2 (narrower infertility definition), and Model 3 (excluding idiopathic infertility, prespecified as the primary model). Cox proportional hazard models were applied to estimate adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs).

In Model 3, women with earlier menarche had an aHR of 1.16 (95% CI: 0.88-1.53) for infertility, whereas those with later menarche had an aHR of 1.28 (95% CI: 0.95-1.72), compared with women with average menarche. Among men, no associations were observed.

Women with earlier or later menarche tended to have a higher risk of infertility than those with average menarche. However, confidence intervals were also compatible with no association. No associations were observed for age at voice break and infertility among men.